Visiting beautiful rainbow ice caves "could be fatal" warns National Park Service

Ice cave at Mount Rainier
(Image credit: Getty)

National Park officials are warning visitors to Mount Rainier not to explore the park's ice caves after a photo of one filled with rainbow-illuminated ice went viral on Instagram.

As IFL Science reports, the photo (which you can see below) shows sunlight hitting the roof of an ice cave, which split it into different colors like a prism. It was taken by photographer Mathew Nichols, who said he couldn't believe his luck, and hadn't enhanced the colors in post-production at all.

"This was by far one of the most magical things I have ever witnessed!!" he wrote. "Even though it was very cold exploring these ice caves I did not want it to end!!"

However, in a statement, the National Park Service has warned visitors to Mount Rainier to be extremely careful, and strongly discouraged them from exploring ice caves to witness the phenomenon for themselves.

The NPS explained that the photo shows a meltwater channel running underneath a perennial snowfield, which are prone to collapsing spontaneously due to increased thawing at this time of year. "Collapse, or ice and rock fall could be fatal or cause serious injuries to those who venture inside or near the entrance," the NPS explained.

Car-sized ice chunks

Park officials also warn that visitors to ice caves are at risk of hypothermia from cold air temperatures, plus colder meltwater from the snowfield. More meltwater will accumulate in caves throughout the day.

"Mount Rainier National Park was known for a few well-developed ice caves, but with the warming climate, those have disappeared, replaced only by transitory and unstable channels/caves," the NPS says. "The park closed the historic ice caves around 1980 due to unsafe conditions including ice chunks and flakes, some the size of a small car, breaking loose and falling from the cave ceiling."

Cat Ellis

Cat is the editor of Advnture, She’s been a journalist for 15 years, and was fitness and wellbeing editor on TechRadar before joining the Advnture team in 2022. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better), usually wearing at least two sports watches.